Electromagnetic switching device

ABSTRACT

An electromagnetic switching device has a housing comprising two housing parts for accommodating contact and terminal parts and a magnetic system. A separate switching chamber is formed in the housing and has outer wall portions integrally formed with the housing parts to provide form-locking support for frame clamps of the device.

United States Patent Piillmann et al.

[ Dec. 25, 1973 ELECTROMAGNETIC SWITCHING DEVICE Inventors: FritzPiillmann; Gerhard Wiissner,

both of Amberg, Germany Assignee: Siemens Aktiengesellschaft, Berlin &

Munich, Germany Filed: May 27, 1971 Appl. No.: 147,317

Foreign Application Priority Data June 3, 1970 Germany P 20 27 137.8

U.S. Cl. 335/132, 335/202 Int. Cl. H0111 50/04 Field of Search 335/132,131, 202,

References Cited UNITED STATES PATENTS 11/1968 Schcib, Jr. et a1.335/132 7/1970 Mullen et a1 335/132 2,908,784 10/1959 Kuhn et a1.335/131 3,320,561 5/1967 Mobarry 335/197 3,194,920 7/1965 Scheib, Jr.335/131 3,230,330 1/1966 Bauer et al. 335/131 3,102,935 9/1963Christeler 335/131 3,238,329 3/1966 Russo 335/131 3,209,096 9/1965Rciner et al.. 335/131 3,534,195 10/1970 Klein et al. 200/166 CT PrimaryExaminer-Haro1d Broome Att0rneyCurt M. Avery, Arthur E. Wilfond, HerbertL. Lerner and Daniel J. Tick [57] ABSTRACT An electromagnetic switchingdevice has a housing comprising two housing parts for accommodatingcontact and terminal parts and a magnetic system. A separate switchingchamber is formed in the housing and has outer wall portions integrallyformed with the housing parts to provide form-locking support for frameclamps of the device.

3 Claims, 3 Drawing Figures SHUT 10. 2

PATENIEDUEEZS I973 Fig.3-

ELECTROMAGNETTQ SWITCHING DEVICE DESCRIPTION OF THE INVENTION Theinvention relates to a switching device. More particularly, theinvention relates to an electromagnetic switching device having ahousing comprising two housing parts for accommodating contact andterminal parts and a magnetic system.

In a switching device of the aforedescribed type, as disclosed in GermanPublished Document DAS No. 1,246,856, the contact parts, the contactslides and the contact bridges are embedded in the housing part and,after the assembly of the switching device, such components aresupported in form-locking relation or are guided in the housing parts.The magnetic system may also be inserted in the housing parts in theknown device. The fixed contact parts with the terminal contacts of thesupport are inserted, at least partly, from outside the housing intoslots of the housing parts and are held in the walls of the housing bydownwardly bent flaps. In this known switching device, the terminalcontacts are free outside the housing and the fastening arrange mentutilizing bent flaps is relatively expensive.

An object of the invention is to provide a switching device having aspecific separation between the parts rated according to the electricalfunction and the parts which must be adjusted in accordance with opticaland mechanical requirements.

An object of the invention is to provide a switching device whichovercomes the disadvantages of known similar types of switching device.

An object of the invention is to provide a switching device of simplestructure which functions with efficiency, effectiveness andreliability.

An object of the invention is to provide a switching device having aswitching chamber utilizing a material having good qualities withrespect to its electrical function but which is generally not utilizedbecause of its mechanical characteristics.

Another object of the invention is to provide a switching device inwhich the individual components may be installed with facility, rapidityand simplicity, due to a switching chamber which is readily accessiblefrom all sides.

Another object of the invention is to provide a switching device havingopen clamps in which the clamping screws are prevented from being lostin transit.

Another object of the invention is to provide a switching device whichprevents tightening of the clamping screws due to jarring duringtransit.

Another object of the invention is to provide a switching device whereinthe MP conductor for the winding connection may be inserted through anadditional terminal screw.

Still another object of the invention is to provide a switching devicewhich permits facile removal of the winding and facile opening of thehousing parts without damage to the terminal wires.

In accordance with the invention, the aforedescribed specific separationbetween the electrically rated parts and the mechanically rated parts isprovided by a separate switching chamber formed in the housing.

In accordance with the invention, an electromagnetic switching devicehaving a housing comprising two housing parts for accommodating contactand terminal parts and a magnetic system comprises a separate switchingchamber formed in the housing.

The separate switching chamber has outer wall portions integrally formedwith the housing parts to provide form-locking support for frame clamps.

A frame having internally threaded bores formed there in frame clampsare provided. Each of the frame clamps has a terminal clamping screwhaving a head and an externally threaded conical end threadedly engaginga corresponding one of the bores. The separate switching chamber isspaced from the housing parts by a length distance corresponding to theheight of a frame clamp plus the length of the terminal clamping screwless the conical end of the terminal clamping screw to accommodate theframe clamps. The housing has openings formed therethrough each locatedover the head of a corresponding one of the terminal clamping screws andeach of a cross-sectional area smaller than the cross-sectional area ofa terminal clamping screw. The head of each of the terminal clampingscrews has a recess formed therein to accommodate a test plug.

Winding leads extend between the separate switching chamber and thehousing parts. The magnetic system has a winding connected at each endto a winding lead.

Each of the housing parts has a projection formed therein on the insideof the housing and each of the winding leads is of bar-shape having anopening formed therein in engagement with a corresponding one of theprojections.

A winding lead has a bent end extending through the housing to outsidethe device. An additional terminal clamping screw is affixed to the bentend of the winding lead.

The winding has ends, and contact springs are in electrical connectionat one end with a corresponding end of the winding and in electricalconnection at the other end with a corresponding winding lead. Each ofthe contact springs is in force-locking connection between acorresponding end of the winding and a corresponding winding lead.

The switching device of the invention permits the separate switchingchamber to comprise high quality material having good qualities withrespect to its electrical function, but which could not be utilized forthe mechanical factors required for the housing. The optical qualtiiesneed not be considered when selecting the material for the switchingchamber, since said switching chamber is covered. Since the separateswitching chamber is readily accessible from all sides, and alsotransversely to the closing direction of both housing parts, theindividual components may be installed in the switching device withsimplicity, rapidity and facility. All the openings required formounting the switching device are closed by the housing parts aftertheir assembly.

The frame clamps are supported in form-locking arrangement in aparticularly simple manner when the outer wall portions of the separateswitching chamber are integrally formed with the housing parts. Thearrangement of the clamping screws permits the switching device to bedelivered with open clamps while preventing the loss of said screws intransit. The clamping screws are also prevented from tightening duringjarring of the switching device in transit, since a clamping screw wouldhave to lift the frame in order to accomplish this. The head of eachclamping screw is provided with a recess formed therein to accommodate atest plug, since the terminal parts are almost completely covered.

The extending of the winding lead for the winding of the magnetic systembetween the separate switching chamber and the housing parts permits theinsertion of the terminal clamping screws in the same height or level.The tight bearing of the housing parts against the separate switchingchamber permits projections formed inside the housing to engage openingsformed in the bar-shaped winding leads, thereby permitting a bent end ofa winding lead to be guided through the wall of a housing part and to beprovided with an additional terminal clamping screw. This permits the MPconductor for the winding connection to be pushed or pulled through atthe additional terminal clamping screw. The provision of a contactspring for the winding of the magnetic system in force-locking contactwith the winding lead when a housing part is in an assembled condition,permits the removal and exchange of the winding with rapidity, facilityand simplicity without damage to the terminal wires.

In order that the invention may be readily carried into effect, it willnow be described with reference to the accompanying drawings, wherein:

FIG. 1 is a lateral section through a contact path of an embodiment ofthe switching device of the invention;

FIG. 2 is a lateral section through the center of the embodiment of theswitching device of FIG. 1, in which the winding connections are shown;and

FIG. 3 is across-sectional view of the embodiment of I the switchingdevice of FIG. 1.

In the FIGS., the same components are identified by the same referencenumerals.

The electromagnetic switching device of the invention, as shown in theFIGS., comprises two housing parts 1 and 2. The housing parts 1 and 2form the housing of the switching device which housing accommodates amagnetic system comprising a stationary magnetic component 3, a movablemagnetic component 4 and a winding 5, as shown in FIG. 1. The housingpart 1 has two projections6a and 6b formed on the inside thereof and thehousing parts 2 has two projections 6'a and 6' formed on the insidethereof. The projections 6a, 6b, 6'a and 6'b support the winding 5.

The movable magnetic component 4 is connected to a contact bridgecarrier 7 which supports contact bridges 8. The contact bridges 8cooperate with fixed contacts 9 and 9'. Contact pressure springs 10provide contact pressure and are located in the contact bridge carrier7. The fixed contact parts 9 and 9' are connected to electricalconductors from outside the switching device via frame clamps 11. Theframe clamps l1 accommodate the free ends 12 and 12' of the fixedcontact parts 9 and 9', respectively.

Each frame clamp 11 has a terminal clamping screw 13. The frame clamps11 are separated from the actual switching chambers which enclose thecontact bridges 8 and the fixed contact parts 9 and 9. The separation ofthe frame clamp 11 from the switching chambers is provided, inaccordance with the present invention, by a separate switching chamber14. The separate switch- -ing chamber 14 may also be utilized to supportand guide frame clamps 1 1. In order to accomplish this, the

separate switching chamber 14 is provided with outer wall portions 15and 16 integrally formed with the housing part 1 and outer wall portions15' and 16 integrally formed with the housing part 2. The frame 20 ofeach frame clamp 11 is guided on the outer wall portions 15 and 16 whenthe terminal clamping screw 13 is loosened, or turned so that it movesupward.

Each of the housing parts 1 and 2 has an opening 17 formed therethroughover the head of each terminal clamping screw 13. Each of the openings17 has a cross-sectional area smaller than the cross-sectional area of aterminal clamping screw 13. The opening 17 is to permit the introductionof a screw driver to turn the terminal clamping screw 13 in eitherdirection.

Each terminal clamping screw 13 has a conical end 18 adjacent theopening in the frame 20. The terminal clamping screws 13 are maintainedin the housing without loss. The movability of each terminal clampingscrew transverse to its longitudinal axis is so limited by the separateswitching chamber 14 and the corresponding housing part '1 or 2 that theterminal clamping screws are prevented from slipping out of the housingvia corresponding openings 19 formed in the frame 20 at their conicalends 18.

During the assembly of the switching device of the invention, the needfor turning the terminal clamping screw 13 is eliminated, therebypermitting a simplification in mounting. Furthermore, the terminalclamping screws 13 are prevented from loosening when the switchingdevice is connected to its mounting. The conical end 18 of each terminalclamping screw 13 is externally threaded and threadedly engages internalthreading provided in each of the openings 19 when the screw is turnedin the proper direction. It is therefore only necessary, at the place ofmounting, to insert outside insulated conductors into corresponding onesof insertion funnels 21, a plurality of which are provided in thehousing parts 1 and 2. When an outside electric conductor is insertedinto a corresponding insertion funnel 21, the corresponding frame 20 islifted due to the pulling up of the corresponding terminal clampingscrew 13, as shown on the left-hand side of FIG. 1.

Each of the terminal clamping screws 13 has a recess 22 formed in itshead, as shown in FIG. 1, to accommodate a test plug. On one hand, theends 12 of .the fixed contact part 9 brace against inwardly extendingprojections 23 formed in the housing parts 1 and 2. On the other hand,as shown in FIG. 3, the ends 12 of the fixed contact part 9 abut theseparate switching chamber 14 in grooves, recesses, or the like, 24formed in said separate switching chamber, thereby providing aforcelocking support.

FIG. 2 shows winding leads 25 and 25 extending between the separateswitching chamber 14 and the housing parts 1 and 2, respectively. Eachwinding lead 25 and 25' comprises a bar-shaped electrical conductorhaving an opening 25a and 25'a, respectively, formed therein. Inwardlyextending projections 26 and 26' of the housing parts 1 and 2,respectively, are in engagement with corresponding openings 25a and 25'a of the winding leads 25 and 25. This permits the shifting of thewinding leads 2S and 25. The winding lead 25 has a bent end 27 whichextends out through the wall of the housing part 2. The bent end 27 ofthe winding lead 25' is provided with a threaded boss 28 having anadditional terminal clamping screw 29 in threaded engagement therein.The additional terminal clamping screw 29 permits the insertion of anoutside PM conductor for connecting the magnetic winding 5.

The electrical connections between the ends of the winding 5 and thecorresponding winding leads and 25' are provided by springs and 30",respectively. The springs 30 and 30 are of leaf type, and pass throughelectrically insulating material 30a and 30a, respectively, on theoutside of the winding 5. Each of the springs 30 and 30' is inelectrical connection at one end with an end of the winding 5 and inelectrical connection at the other end with the corresponding windinglead 25 or 25'.

When the switching device 7 of the invention is mounted, the bridgecontact carrier 7 is first led through a guide opening 31 in theseparate switching chamber 14 and is connected to the movable magneticcomponent 4. The fixed contact parts 9 and 9' are affixed in a simplemanner, either before or after the positioning of the bridge contactmember, depending upon whether a closing or opening contact is present.The fixed contact parts 9 and 9 are merely inserted into correspondingones of grooves 32 formed in the separate switching chamber 14. The ends12 and 12' of the fixed contact parts 9 and 9, respectively, whichcooperate with the projections 23 and 23 formed in the housing parts 1and 2, respectively, prevent said fixed contact parts from sliding back.

The frames 20 are guided across the ends 12 and 12 of the fixed contactparts 9 and 9, respectively (FIG. 1), or bent parts 33 and 33 of thewinding leads 25 and 25 respectively, engage said frames and are movedso that openings formed in said bent parts engage projections 26a and26'a, respectively, of the housing parts 1 and 2. The terminal clampingscrews 13 are then provided. Thus, after the stationary magneticcomponent 3 and the winding 5 are inserted, the housing parts 1 and 2may be closed on each other.

The electromagnetic switching device is thus of very simple structureand is completely free from impairment in function due to suchsimplicity of structure. On order to enhance the stability of theseparate switching chamber 14 and the housing parts 1 and 2, gears 34may be provided at said separate switching chamber, as shown in FIG. 3.The gears 34 engage the housing parts 1 and 2 in force-locking relation.

While the invention has been described by means of a specific exampleand in a specific embodiment, we do not wish to be limited thereto, forobvious modifications will occur to those skilled in the art withoutdeparting from the spirit and scope of the invention.

We claim:

1. An electromagnetic switching device of the type having contact andterminal parts and a magnetic system, comprising a housing having twohousing halves. means integrally formed on said housing defining aseparate switch chamber within said housing, frame clamp means disposedin said chamber for receiving and clamping electrical conductors, saidchamber defining means having support means for mounting and movablysupporting said frame clamp means within said chamber to provide forsaid frame clamp means effecting a clamping action with said electricalconductors, said frame clamp means comprising frame clamps havinginternally threaded bores formed therein, each of the frame clampshaving a terminal clamping screw disposed within said chamber and havinga head and an externally threaded conical and threaded engaging acorresponding one of said bores, said chamber defining means comprisinginternal wall means spaced from an opposite end wall of said housing bya length distance corresponding to the height of a frame clamp plus thelength of the terminal clamping screw less the conical end of theterminal clamping screw, said housing having openings formedtherethrough each located over the head of a corresponding one of theterminal clamping screws and each of a cross-sectional area smaller thanthe cross-sectional area of a terminal clamping screw.

2. An electromagnetic switching device as claimed in claim 1, whereinthe head of each of the terminal clamping screws has a recess formedtherein to accommodate a test plug.

3. An electromagnetic switching device as claimed in claim 1, whereinsaid two housing halves each has a portion defining one-half of saidchamber, said termi nal clamping screws being received in said bores ofsaid frame clamps before said housing halves are assembled whereby afterassembly, said terminal screws are not removable from their respectivebores so that said device may be initially provided with open frameclamps while preventing the loss of said terminal screws in transit.

1. An electromagnetic switching device of the type having contact andterminal parts and a magnetic system, comprising a housing having twohousing halves, means integrally formed on said housing defining aseparate switch chamber within said housing, frame clamp means disposedin said chamber for receiving and clamping electrical conductors, saidchamber defining means having support means for mounting and movablysupporting said frame clamp means within said chamber to provide forsaid frame clamp means effecting a clamping action with said electricalconductors, said frame clamp means comprising frame clamps havinginternally threaded bores formed therein, each of the frame clampshaving a terminal clamping screw disposed within said chamber and havinga head and an externally threaded conical and threaded engaging acorresponding one of said bores, said chamber defining means comprisinginternal wall means spaced from an opposite end wall of said housing bya length distance corresponding to the height of a frame clamp plus thelength of the terminal clamping screw less the conical end of theterminal clamping screw, said housing having openings formedtherethrough each located over the head of a corresponding one of theterminal clamping screws and each of a cross-sectional area smaller thanthe cross-sectional area of a terminal clamping screw.
 2. Anelectromagnetic switching device as claimed in claim 1, wherein the headof each of the terminal clamping screws has a recess formed therein toaccommodate a test plug.
 3. An electromagnetic switching device asclaimed in claim 1, wherein said two housing halves each has a portiondefining one-half of said chamber, said terminal clamping screws beingreceived in said bores of said frame clamps before said housing halvesare assembled whereby after assembly, said terminal screws are notremovable from their respective bores so that said device may beinitially provided with open frame clamps while preventing the loss ofsaid terminal screws in transit.